The present invention relates to a manually operated dispensing, distributing or delivery apparatus with a pump for the discharge of media from a storage vessel or the like. The invention operates in a normal or upright position and also in an opposite, inverted position of the apparatus.
A delivery apparatus of this type is known (German patent 28 18 560), in which a pump chamber defined by a cylinder and a pump piston displaceable therein is filled in the inverted position through an opening in the cylinder wall, whilst in the opposite normal position it is filled through a suction hose provided at the free end of the cylinder. Two checks valves are interposed. The latter suction connection must be closed by one of the check valves during the suction stroke to obtain an adequately high suction volume in the inverted position. However, during the pump stroke, said suction connection must be closed both in the normal and in the inverted position. This operation requires a very fine coordination of numerous factors, e.g. the weight of the ball valves, the flow cross-sections and the like. Therefore, satisfactory operation with this delivery apparatus cannot be achieved in both positions, particularly in view of the very small construction of such pumps and differences in manual operation.